Re: [Qemu-devel] [PATCH 1/2] vl: Fix the confused logic for '-m' option

[zhanghailiang <zhang.zhanghailiang@huawei.com>]

On 2014/9/12 21:52, Igor Mammedov wrote:
> On Fri, 12 Sep 2014 13:58:55 +0800
> zhanghailiang<zhang.zhanghailiang@huawei.com>  wrote:
>
>> It should be valid for the follow configure:
>> -m 256,slots=0
>> -m 256,maxmem=256M
> Doc comment/help says that slots&  maxmem must be in pair so above is not valid CLI
> "

Hmm, yes, you are right;), Sorry for the noise.

> -m[emory] [size=]megs[,slots=n,maxmem=size]
>                  configure guest RAM
>                  size: initial amount of guest memory (default: 128MiB)
>                  slots: number of hotplug slots (default: none)
>                  maxmem: maximum amount of guest memory (default: none)
> "
>
>> -m 256,slots=0,maxmem=256M
>> -m 256,slots=x,maxmem=y  where x>  0 and y>  256M
> s/-m 256,slots=x,maxmem=y  where x>  0 and y>  256M/-m z,slots=x,maxmem=y  where x>  0 and y>  z(M)
>
>>
>> Fix the confused code logic and use error_report instead of fprintf.
>>
>> Printing the maxmem in hex, same with ram_size.
>>
>> Signed-off-by: zhanghailiang<zhang.zhanghailiang@huawei.com>
>> ---
>>   vl.c | 46 +++++++++++++++++++++++++++-------------------
>>   1 file changed, 27 insertions(+), 19 deletions(-)
>>
>> diff --git a/vl.c b/vl.c
>> index 9c9acf5..f547405 100644
>> --- a/vl.c
>> +++ b/vl.c
>> @@ -3306,6 +3306,7 @@ int main(int argc, char **argv, char **envp)
>>                   break;
>>               case QEMU_OPTION_m: {
>>                   uint64_t sz;
>> +                uint64_t slots;
>>                   const char *mem_str;
>>                   const char *maxmem_str, *slots_str;
>>
>> @@ -3353,40 +3354,47 @@ int main(int argc, char **argv, char **envp)
>>
>>                   maxmem_str = qemu_opt_get(opts, "maxmem");
>>                   slots_str = qemu_opt_get(opts, "slots");
>> -                if (maxmem_str&&  slots_str) {
>> -                    uint64_t slots;
>> -
>> +                if (maxmem_str) {
>>                       sz = qemu_opt_get_size(opts, "maxmem", 0);
>> +                }
>> +                if (slots_str) {
>> +                    slots = qemu_opt_get_number(opts, "slots", 0);
>> +                }
>> +                if (maxmem_str&&  slots_str) {
>>                       if (sz<  ram_size) {
>> -                        fprintf(stderr, "qemu: invalid -m option value: maxmem "
>> -                                "(%" PRIu64 ")<= initial memory ("
>> +                        error_report("qemu: invalid -m option value: maxmem "
>> +                                "(%" PRIx64 ")<  initial memory ("
> it may be worth to add 0x before hex number,
> maybe printing maxmem_str instead of number here would be better, since
> user would able to match easily maxmem value and what is printed in error message.
>

Good idea, will fix it.

>
>>                                   RAM_ADDR_FMT ")\n", sz, ram_size);
>>                           exit(EXIT_FAILURE);
>>                       }
>> -
>> -                    slots = qemu_opt_get_number(opts, "slots", 0);
>> -                    if ((sz>  ram_size)&&  !slots) {
>> -                        fprintf(stderr, "qemu: invalid -m option value: maxmem "
>> -                                "(%" PRIu64 ") more than initial memory ("
>> +                    if (!slots&&  (sz != ram_size)) {
> it would report wrong message in case of "-m 256,slots=0,maxmem=128M"
>

No, in this case, actually it will go into the above *if (sz<  ram_size) {*
branch statements and reports "qemu: invalid -m option value:
maxmem (8000000) < initial memory (10000000)":)


>> +                        error_report("qemu: invalid -m option value: maxmem "
>> +                                "(%" PRIx64 ") more than initial memory ("
>>                                   RAM_ADDR_FMT ") but no hotplug slots where "
>>                                   "specified\n", sz, ram_size);
>>                           exit(EXIT_FAILURE);
>>                       }
>> -
>> -                    if ((sz<= ram_size)&&  slots) {
>> -                        fprintf(stderr, "qemu: invalid -m option value:  %"
>> +                    if (slots&&  (sz == ram_size)) {
> What takes care about the case "-m 256,slots=1,maxmem=128M"?
>

Same with the above explain.

>> +                        error_report("qemu: invalid -m option value:  %"
>>                                   PRIu64 " hotplug slots where specified but "
>> -                                "maxmem (%" PRIu64 ")<= initial memory ("
>> +                                "maxmem (%" PRIx64 ") = initial memory ("
>>                                   RAM_ADDR_FMT ")\n", slots, sz, ram_size);
>>                           exit(EXIT_FAILURE);
>>                       }
>>                       maxram_size = sz;
>>                       ram_slots = slots;
>> -                } else if ((!maxmem_str&&  slots_str) ||
>> -                           (maxmem_str&&  !slots_str)) {
>> -                    fprintf(stderr, "qemu: invalid -m option value: missing "
>> -                            "'%s' option\n", slots_str ? "maxmem" : "slots");
>> -                    exit(EXIT_FAILURE);
>> +                } else if (!maxmem_str&&  slots_str) {
>> +                    if (slots>  0) {
>> +                        error_report("qemu: invalid -m option value: missing "
>> +                                "'maxmem' option\n");
>> +                        exit(EXIT_FAILURE);
>> +                    }
>> +                } else if (maxmem_str&&  !slots_str) {
>> +                    if (sz != ram_size) {
>> +                        error_report("qemu: invalid -m option value: missing "
>> +                                "'slot' option\n");
>> +                        exit(EXIT_FAILURE);
>> +                    }
>>                   }
>>                   break;
>>               }
>
>
> .
>